The present disclosure relates to a signal processing circuit of a solid-state imaging element, a signal processing method of a solid-state imaging element, and an electronic apparatus.
In a solid-state imaging element, an output signal which is almost linear with respect to the amount of charge accumulated by photoelectric conversion may be obtained from a unit pixel. A dynamic range of the solid-state imaging element is determined primarily by the amount of charge (amount of saturated charge) capable of accumulating the unit pixel and a noise level. That is, the lower limit of an output level of the solid-state imaging element is restricted by the noise level, and the upper limit thereof is restricted by the saturation level. As a result, the dynamic range of the solid-state imaging element is determined primarily by the amount of saturated charge and the noise level.
As a method for expanding the dynamic range, it is widely used of synthesizing an image which is imaged by charge accumulation for a long time and of which a low luminance portion is relatively clear, and an image which is imaged by charge accumulation for a short time and of which a high luminance portion is relatively clear. As one technologies in the related art, which realizes a wide dynamic range, a technology in which a plurality of image signals with different exposure times are input, and the input signals are weighted by a value which is determined primarily has been used (for example, Japanese Unexamined Patent Application Publication No. 2004-266347).